MODELING AND STUDY of flapping wing

Gtu team id no. 7250

MITHILESH J PARMAR 110410101054DHAVAL AARYA 110410101046BHOI VINITA 090410101058

Guide- CAPT. U N JANI

• Content• Abstract• Introduction• Literature review1. Working2. Taking off and landing3. Controls4. Principle or law of working

Abstract

• Flapping wing is the version of single sitter personal-utility aircraft in which we don't have fuselage, which is one of the biggest non-lifting and drag producing structural member of any aircraft. By eliminating fuselage we can greatly reduce weight of the aircraft which must be the most considerable thing while designing the aircraft to reduce empty weight of aircraft. In this design we are flapping the wings with the help of actuators operated by electrical motor. By flapping the wings we can produce lift for what wings are to be designed and wings are also producing thrust as well. So, for production of thrust we don't require engine, which also reduces weight of the aircraft. By using electrical energy in place of ordinary jet fuels we can greatly reduce the flight cost as well.

• Now in our project, we will carried out MODELLING and STUDY . In study of Aerodynamic behaviour of Flapping wings and verify them with the results of project FALCON 12a.

• Douglas C. George is the founder of this flapping wing concept project FALCON 12a.

• Introduction

• In this project we are designing and studying the concept of Falcon 12a which was prepared by D.c.George one of the historic archaeologists in Minnesota in United states.

• We are studying the design in Matlab for aerodynamic forces and behavior.

• In this we are measuring the force produced by each pinion in the wing separately and summing then to get the total force produced by whole wing.

• From this design we are trying to check the validation of this design that weather it can fly or not.

• This design doesn’t having fuselage which is the main non-lifting component of the aircraft .

• So, empty weight of this design is greatly reduced.

• In this design we are using electrical energy to drive the flapping mechanism so, we get great reduction in fuel cost as well, because electrical energy is quite cheap with comparison to ordinary jet fuels used In aviation industry.

• In this design for getting sufficient lift to takeoff we only require 14Mph speed which human can easily achieved by running.

• Because of foldable wing design it can fit in very less space and we can easily transport.

• Literature review • Douglas C. George was one of the premier historic archaeologists in Minnesota in United

states. He was the one who thought about this flapping wing ornithopter and made a design and named as Falcon12a.

• The lift production of each wing element is then determined using NASA’s FoilSim II airfoil simulator. Other data about his project which we are using as reference is as follow.

• With the advantage of carbon fibre composites, expanded foam structures, exotic alloys, computerized electronic control systems and modern compact power sources, the dream of flying like a bird is possible now for mankind.

• The project is a light-weight, strap-on, exoskeleton aircraft coupled to your back with hydraulic controlled interface. It transforms your arms and hands into bird wings. The wing movements are driven by hydraulic pistons pressurized by a electric motor driven by battery packs.

• The wings and hydraulic actuator unit are mounted behind your shoulders. You transform into the exoskeleton cage, sticking your arms out through the side openings and strap the whole thing down like a backpack. Then, grab hold of the hand grips and you're ready to fly.

• Working

• Taking off and landing• it's probably not possible with this ornithopter to take off in steady position on level ground.

Most likely, take-off will require a gentle higher upwind speed, Simulator studies indicate that, for an aircraft with this wing area, 288 lbs of lift is obtained at 14 MPH. Since humans can easily run at this speed, a running take-off is most suitable for this design envelope. Landing would be a matter of gliding down at the slowest possible airspeed and performing a stall maneuver at the last second, just as your feet touch the ground.

Haptic Interface

• A haptic interface is a sensing and feedback mechanism that acts as the interpreter between a human and a robotic device. The interface senses the human's actions and returns information about the state of the device. The Falcon employs two such interfaces, one for each wing. Each interface includes a hand grip, two sensors and a small parallelogram.

• Wing motions are initiated by either lifting, rotating or pulling on the handgrips.

• As shown in fig., the hand grip and sensors are mounted on a small parallelogram attached to the larger parallelogram of the wings' humerus section. The same cable-gear devices as used in the wing joints are used in the interface joints to force the interface and your arm to mimic the folding motions of the wing. The hand section of the interface tracks both the horizontal rotation (radial deviation) of the outermost wing section and imitates its vertical flexion. Because the human wrist has a lesser range of motion in the horizontal plane, the radial deviation of the interface's hand-section is less than the rotation of its counterpart in the wing

• The only connection between you and the aircraft (other than being strapped in) is through the two hand grips. You simply grasp the hand grips and move your arms and hands in an appropriate manner. The haptic interfaces detect your motions and direct the hydraulic actuators to move the wings in a corresponding manner. All the while, you receive constant feedback about the configuration of and forces acting on the wings.

• Feedback is achieved in two ways. First, the centres of the joints of the small parallelograms are closely aligned with those of your wrist and elbow joints. This insures that your arm positions and motions coincide with those of the wings. The other means of feedback has to do with how the hand grips pivot. When the wing begins to swing upward, the outer section relaxes and bends downward. When you lift up on a hand grip to initiate the back-swing, the fact that it is hinged distally to your hand, causes your wrist to, likewise, bend downward. The two motions coincide. In this manner, you get feedback with no actual linkage between your hand and the wing's hand section.

Flapping Control: An electronic sensor (shown in gray in the drawing above) mounted on the flapping-control-axis of the hand grip detects vertical motions of your arm and activates the large actuator to move the wing in the corresponding direction.

Pitch and Roll Control: Rotating the hand grips about their pitch-control axes cause the aircraft to either pitch or roll. Sensors aligned along the pitch-control axes of the interfaces detect those rotations and direct the small actuators to rotate the wings about their long axes accordingly. Turning one grip at a time causes the craft to roll. Turning both grips in opposite directions results in a more extreme roll. Rotating them in the same direction will result in pitching the nose either up or down.

Yaw Control: Like with birds, our ornithopter has no direct yaw control that is independent of motion around the other two axes. Rotation of a hand grip on one wing to initiate a roll, for example, will naturally include "adverse yaw" as the pitched wing is dragged backward due to the added drag on that side. If the right hand grip is rotated for a downward pitch, the aircraft will roll to that side and the right wing will be dragged backward, resulting in a properly banked turn.

• Principle or law of working

• according to Edward Tufte's video, taken at 300 frames-per-second, of geese taking flight reveals that the flapping flight of birds is less complicated than previously thought. Birds employ a relatively simple scheme to accomplish what appears to be a complex set of motions.

• The power-stroke of the flapping cycle is simple and straight forward; the wings sweep downward and forward while stretched out flat with the joints locked.

• During the backstroke, a bird simply relaxes its wrist joints and allows its hands to fall limp while simultaneously folding its wings inward. The relaxed hand-sections, caught up in the wind stream, are quickly lifted and thrown backward requiring little or no effort on the part of the bird.

• Further simplifying the process, as the wing folds, a parallelogram arrangement of the arm bones keeps the hand and humerus sections aligned.

• As shown below, the Falcon wing forearm includes such a parallelogram structure. The illustration shows the wing in three stages of extension. Note that the hand section stays parallel to the humerus section in all three positions.

• Unlike in a bird, the humerus section in the Falcon wing is also a parallelogram mechanism. Its purpose is to prevent any forward or backward sweep of the wing during the folding process. As will be explained below, this makes the power-stroke function much simpler and provides for a clean separation between the three control functions.

• Flapping motions of the wing (the power-stroke and backstroke) are confined to a single plane called the power-stroke plane(illustrated below), determined by the tilt of the shoulder joint axis. The power-stroke plane is both down and forward (as it is with birds).

• This arrangement allows for a mechanically simple power-stroke in which the stroke angle can be adjusted for optimal efficiency and the entire flapping function is cleanly separated from the wing-folding and pitch-control functions. More importantly, it allows the entire flapping sequence to be powered by only one hydraulic piston per wing.

• A bird's hand section is equivalent to the business end of a boat's oar, driving the bird forward as well as upward. The Falcon's hand section, as in a bird wing, will be designed to twist during a power-stroke to tilt the lift vector more forward than it is for the inner two wing sections. In the bird wing and the Falcon's wing, the inner two sections maintain a relatively fixed angle of attack to the wind and so provide varying amounts of lift during all phases of the flapping cycle.

• All of these factors add up to a simplified flapping cycle for the Falcon that insures a clean separation between the various power and control functions.

• Wing folding• Birds fold and extend their wings during flight for many reasons. They fold

them to gain airspeed, to dump excess forces, to maintain headway in a stiff wind and, as mentioned, they fold them during the backstroke phase of the flapping cycle.

• Wing folding

• Birds fold and extend their wings during flight for many reasons. They fold them to gain airspeed, to dump excess forces, to maintain headway in a stiff wind and, as mentioned, they fold them during the backstroke phase of the flapping cycle.

• Since the lift and drag forces acting on the wings are generally perpendicular to the force needed to fold them up, our ornithopter wings are folded up using only the pilot's arm muscles.

• The wings are tension loaded to maintain full extension. The tension will be adjusted to allow the wing folding process to be done by arm-power alone. You simply pull the hand grips inward to fold the wings and relax your arms to let the wings spring back to their extended positions.

• Advantages• This design doesn’t having fuselage which is the main non-lifting component of

the aircraft .

• So, empty weight of this design is greatly reduced.

• In this design we are using electrical energy to drive the flapping mechanism so, we get great reduction in fuel cost as well, because electrical energy is quite cheap with comparison to ordinary jet fuels used In aviation industry.

• In this design for getting sufficient lift to takeoff we only require 14Mph speed which human can easily achieved by running.

• Because of foldable wing design it can fit in very less space and we can easily transport.

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